Apparatus for transfer of heat in gaseous media



July 8, 1952 N. s. JAPOLSKY Filed Oct. 25, 1947 APPARATUS FOR TRANSFER OF HEAT IN GASEOUS MEDIA APPARATUS FOR TRANSFER OF HEAT IN GASEOUS MEDIA I Filed Oct. 25, 1947 July 8, 1952 N. s. JAPOLSKY 2 SHEETS'SHEET 2 fm/ewfor Afr/mus 6. Jmozsm 4 the partitions 36 are seen and it will be observed that these partitions can efiectivelyconsist of a single plate which is bent to a sinuous shape.

In order to assist in the understanding of the course of the channels provided in the rotor 'I,

reference will now be made to the diagrams of Figures 6 and 7. In these figures it is supposed that the channels have been straightened and simplified. The return channel portion 34 is seen to communicatewith the return channel-portion 3| through the passages 50.-- These passages a1- ternate with the series of closely spaced passages which all open into the flow portion 3 In the employment of the machine described' above, the rotor! is rotated by a source of mechanical power, and as a result air is drawn in also be obvious that the air leaving the channel 20 will be at a higher temperature than the air entering the channel l9, and moreover the air leaving the channel 29 will be at a higher temperature than th air entering the mouth l0.

As illustrated in the drawings, the flow channel is indicated at 30 and the return channel is indicated at 3| and 34. In Fig. 1, it will be seen that the return channel 3! and 34 passes just behind the flow channel 30 over an area indicated at the section line VV. In this area (see Figs. 4, 5 and 6), numerous partitions 50 and 5| exist. which ensure that heat exchange is promoted. Fig. 6 represents a simplification of the flow channels3ll and the return channels BI and 34 by simply straightening them in regard to the path of motion of the fluid therein, whereby such at'IU and moves centrifugally through the channel portion 34; In flowing centrifugally in this manner, the air is at first adiabatically compressed and then passes through the passages 50 in the zoneof narrow passageways. -In flowing in' this zone compres'sioncontinues, butfor reasons that will become clear from the following description, the compression isthen substantially isothermal. The return path of the air is'completed by centripetal motionthrough the channel portion 3!, wherein adiabatic expansion takes place. {The motion :of the air from the channel 34 to the channel 3| commences and continues by reason of thefact that-the radial column of air associated with the channel 34 isconsiderably longer than that of channel 3!." simultaneously with the return motionof the air, the flow mo- 1 tion proceeds, this motion consisting essentially of entry of a stream of air through the inlet l9 into the portion 3i of the outer channel where there is adiabatic compression with the air moving centrifugally. Thereafter the air passes through the passages 5i and leaves from the mouth 37, the motion being then centripetaland being accompanied by an isothermal expansion.

The air passes into the annular space l8 and leaves the machine at the outlet 20. Thus air maybe regarded as drawn into the mouth 10 and expelled through the mouth l5. Air will also'be drawn'into the mouth I9 and expelled through the mouth 20. The initial adiabatic'compression-occurring in the how channel 30 -will'cause the temperature of the air to rise. A Isothermal expansion in the passages 5 [will tend to result in air delivery at the temperature reached after the adiabatic process. Clearly, in order to'carry out an isothermal expansion, heatmust be delivered to the air 'during the' isothermal process, and this is achieved by reason of the adiabatic compression which takes place in the initial part 34 of the return channeland the subsequent isothermal compression in the passages 50 during 2 heat exchange. The final adiabatic expansion carried on in the return channel 3| will of course result in lowering of'the temperatura'and it is therefore to be expected that the-air leaving from the mouth 15 will be at a lower temperature than the air entering'the mouth I0. It will tially the same.

,, channels may be regarded as being upon a .cylindrical surface with axis located at the axis of the shaft 2 (Fig. 1). In Fig. 5 the diagram maybe regarded as a development of the cylindrical surface obtained by straightening the channels 3il, 3l and 34.

Referring again to Fig. 1, the return channel .34 has a greater radial extent than return channel 1 3| ,which will promote a flowfrom the longer to' the shorter channel. The radial extent of the two columns of flow channel 30 is substan-y While it might be advisable to.

have thetwo columns of the flow channel of different lengths, it is not necessary because A in the initial operation of the. machine .the. adiabatic compression occurring. in the first. part of the return channel andthe subsequent isothermal compression provided sufiicient heat to raise the temperature in one column of the flow channel. The raising oftemperature in this way insures-that the density ofthe air in the one, column of the flow channel results in the. nece -Z 'sary unbalance to ensure a desired counterflow 1 in the flow channel. Y

If the vtwo channels both had precisely similar thermodynamic processes proceeding in'eachone of them but oppositely directed, the transfer of' heat between the air streams in the two channels would tend to keep the two air streams5at constant temperature. However, it will be seen that i air enters the return channel and first unders,

goes adiabatic compression whereby the temperature rises. Thereafter, compression con-- tinues in the return channel, but this compression proceeds in a large number of passageways made of conducting material which ensure that 7 there can be heat exchange with the air in the overlapping part ofthe flow channel. Thus the compression continues in a non-adiabatic fash ion and tends to be isothermal with heat being imparted to the air in the flow channel. Continuing further the progress of air in the return channel, after the isothermal compression is ended, an adiabatic expansion proceeds in the righthand column of the return channel without,

further heat exchange with the air in the flow channel. Considering now the equivalent series I of thermodynamic operations in theflow channel,cit will be realized that'air enters the flow channel and undergoes an adiabatic compression thereby experiencing a temperature rise until the air enters the region where heat exchange, can take place with the airin the return channel. In the heat exchange region, expansion of the air in theflow channel takes place, butheat is received from the.return channel air and hence expansion' ofztheg flow channel air takes place substantially isothermally. Following the isothe reason that the air column radially extendcause a reduction call-y" followthatthe-temperature at which the flow air is expelled willbe higher than the temperature at which-such air is'taken into the flow channel. v, v

The P. V. diagram for the machineisshown in Fig. 7 and the -T-. .S. is shownin Fig 8-.- The used air from the building enters the pump at H and is. compressed adiabatically" v the fl'anblading-to the point -'I Twhere it enters the heat exchangersection. Thefr'esh'air from the atmosphere enters at" 14- and" is also compressed adiabatically up to point 15 where it enters the opposite end of the heat exchange section. The adiabatic compression of both used and fresh air is so adjusted that after compression they are at the same temperature, and since the used air enters the machine at a higher temperature than the fresh air, the amount of compression given to the used air is correspondingly less. The two streams are then led through the heat exchanger section in opposite directions, the used air being compressed further by centrifugal force to the point 12 and the fresh air expanding centripetally to the point 15. Since the facilities for easy heat exchange are provided and since both streams of air enter the heat exchanger at the same temperature, compression and expansion in the heat exchanger takes place isothermally. After passing through the heat exchanger, the fresh air, now heated and expanded to atmospheric pressure, is led into the building. The used air is allowed to expand back between the heat exchanger sections, so doing work on the rotor and being cooled. It then leaves the machine and is exhausted to atmosphere at a temperature below the atmospheric temperature.

The various stages of the process are indicated on the P. V. and T. S. diagrams in Figs. 7 and 8.

It will be appreciated that the machine works being taken from and on an open circuit, the air finally delivered to the outside atmosphere. The cycle is completed, therefore, by the isobaric heating process 13-44 and l5--ll shown dotted on these diagrams.

In order that those portions of the flow and return channels intended for adiabatic processes should in fact promote adiabatic processes, such channels are as far as possible heat insulated. In the zone where the fiow and return channels run side by side, and where isothermal operations are desired, conditions for maximum heat exchange should be provided. This is indeed the case, since the closely spaced partitions 36 are made from a good heat conducting material, and moreover the immediate proximity of the flow and return passages created by the partitions 36, favours heat exchange.

In the illustration of Figure 1, it appears that the radial extent of the air columns associated with channel mouth 3'! and channel 30 are substantially the same, so that no tendency would apparently exist for the motion of the air directed from channel 30 to the channel mouth The motion commences (and continues) for ing from channel mouth 31, becomes heated due to the heat exchange with the air that has been adiabatically compressed in the channel 34 prior to the heat exchange. Since this heating will indensity of the air in the column associated with the channel mouth 31, the motion commences and proceeds.

In describing the mode of operation of the by th first stage off our, neverthelesshr promote appropriate conditions;

purposes" of the present specification? an: iso=- thermal process is' to be c'on'sidered broadl one in which heat exchange is -promoteu 7 w i an adiabatic process is one in: which-heat ca changeis Jredueed.to practical mini-mumi If i'so desired-thefalI in temperaturecaused by the adiabatic expansion in the return channel portion 3|, could be employed to reduce the humidity of air entering the flow channel portion 30, by arranging for a pro-cooling operation on the air entering the inlet [9.

The construction of the machine shown in the drawings represents a useful form for raising of the temperature of the air within a building. The mouth I0 can be arranged to draw air from the building, whilst the mouth 20 delivers thereto air at a higher temperature. Both the mouths l5 and H! can then be open to the atmosphere external to the building. Just as the machine can be used for raising the temperature of a body of air, it can clearly be used for lowering the temperature of a body of air, where a refrigerating or cooling effect is desired. Other applications of the invention will be apparent from considera tion of the principles which underlie the same.

I claim:

1. Apparatus for heat transfer comprising a rotor, bearings for supporting said rotor to permit the same to be rotated about an axis. a flow channel disposed in said rotor and opening at either side thereof, to provide an inlet and outlet for air to and from said fiow channel, a return channel disposed in said rotor and opening at either side thereof to provide an inlet and an outlet for air to and from said return channel, the inlet of one channel being disposed adjacent the outlet of the other, a first zone in said flow channel extending from the inlet side thereof and in which adiabatic compression of air is promoted, a second zone in said flow channel wherein isothermal expansion of said air is promoted, a first zone in said return channel extending from the inlet thereof and wherein adiabatic compression is promoted, a second zone in said return channel wherein isothermal compression is promoted, and means promoting heat exchange in said second zones of the flow and return channels.

2. Apparatus for heat transfer according to claim 1 in which the return channel has a third zone extending to the outlet thereof and wherein adiabatic expansion is promoted in a region adjacent said first zone of the flow channel.

3. Apparatus for heat transfer according to claim 2 in which the flow channel in the rotor is disposed with said first zone having a radial component of direction for the production of centrifugal flow therein whilst the second zone of said flow channel has also a radial component of direction to allow centripetal flow therein, the return channel having the first and second zones thereof disposed with a radial component of direction to promote centrifugal flow therein whilst the third zone of said return channel has a radial component of direction promoting centripetal flow therein.

4. Apparatus for heat transfer according to claim 1 wherein said means for promoting heat Thusfor the-1e aeoasoa- 7 8 7 exchange consist of relatively small adjacentzpasreturn channel and theouter conduit connecting sages which alternately connect with the flow and r with the outlet of said flow channel. return channels and which are made of heat con- NICHOLAS S. JAPOLSKY. ducting material. I I I 5.7 Apparatus for heat transfer according to 5 7 REFERENCES CITED I C m 1 d further comprisinng fi pail The following references are of record in the conduits nested one within the other the inner v file of this patent; conduit being arranged to communicate with the outlet; side of the return channel and the outer UNITED STATES PATENTS conduit beingarranged to communicate with the -10 Number Name Date inlet side of said flow channel, and further com- 2,393,338 Roebuck Jan. 22, 1946 prising a second pair of nested conduits, th in- 2,490,065 Kollsman Dec. 6, 1949 ner conduit communicating with the inletof said 2,490,067 Kollsman Dec. 6, i949 

